First, go to the forge. Up from Vip Depo

Level 700 required to complete the quest

Then follow the road to the right, to the very end, to the last room
And use the lever to switch to custom spawn for lvl 500

Now go down one floor to Instable Goshnar's Malice and follow the road to the end to the left

When you see a prominent tile at the end of the road, use it to turn on the lamps

The lamps will be turned on for one day

Then go back to the beginning of the entrance and use one of the electrified lamps to open Stage 2 of the facility

As you go further, you will come across a sign with a hole to level 700 with no return.
After you go down the hole, prison Goshnars will be waiting for you

You can run fast, but then the doors will open and the Goshnars will run after you!

At the end of the road, you will find a chest from which you can take Green Memory Shard (Upgrade Crystal) once a day